Hydraulic valve



H. E. PAGE HYDRAULIC VALVE July 20, 1948.

'2 Sheets-Sheet 1 Filed Oct. 30, 1943 Jauv az-z-tar' :Hsrbzsrt 5' Pa: 6'

July 20, 1948. H. E. PAGE 2,445,334

Patented July 20, 1948 UNITED T A-TBS ATENT OFFICE 2,445,334 momma VALVE 'Herbert E. 'Pa'ga Pasadena, Calif.

Application October '30, 1943, Serial No. 508,444

a 1 This invention relates to hydraulic valves and, in its more particular aspeets relates' to valves for use in pressure-generating devices such as hydraulic jacks utilizing a work piston and chamber and a pumping piston for gradually'buildingup pressure in the work chamber. 7

Prior tomy invention, hydraulic valves intended for such purposes have been of such construction that it has not been feasible to obtain in a unitary combination structure a valve capable of performing the multiplicity'of functions required, and another rather serious shortcoming has been the fact that'when the hydraulic devices in which such valves are used are under pressure/the back pressure on the check valve admitting fluid to'the pressure chamber considerable, with the result that'with each pumping operation for the purpose of building up'the pressure in the pressure chamber; the operator must overcome not only the fluid back pressure on the check valve, but also the spring pressure normally urging'the check'valv seated.

It is one oftheobject's' of ,my present invention to provide avnve'eleme'nt in which'the'ball valve and/or a valve for admitting fluid to the; work cylinder directly from the reservoir when.

there is a vacuum in the work cylinder.

Another objectis to providenovel means for releasingthe fluid from the chambers, such'for instance, astolower a load lifted by a hydraulic,

jack.

Another object'is the provision of a valve unit which is compact, durable and which maybe readily and easily mounted in a' hydraulic device or removed therefrom for serving in re placement.

pla'natibn of a presently preferred embodiment, it will be apparent to those skilled in thisart that my invention has other objects and featuresof novelty and advantage and; that it is susceptible of being embodied in structures differing specifically in physical characteristics the s't'ructure'no-w' to be described.

For the purposes of thertnawm description "7 cities. (01. 277-60) I shall refer to the accompanying drawings, in

which:

Fig. '1 is a medial vertical sectional view; Fig. 2 is an enlarged section on line 2-2 of Fig. l; Fig. 3 is an enlarged section on line 34 of Fig. l; and i Fig, 4 is an enlarged section'on line 44 of Fig. 1.

Referring to the drawings, I show a body 5 which typically maybe that of a hydraulic jack,

although. it will be understood that myvalve may be employed to equal advantage in other hydraulic devices.

The body presents an annular hydraulic fluid reservoir R, avalve-receiving bore 1, a pumping mounted in cylinder 9, the pumping piston being From, the following detailed'de'scriptionand exactuated as by conventional lever, not shown. For the purposes of the following description, it may be deemed that the workpiston 16 is stationary and the bo y 5 movable, although the device is operable if the body is fixed and the work piston l6 movable. i

Mounted in the bore 1,, and normally retained therein as by a snap ring 29, there is a valve body 22. Mounted in the inner end of the valve body and normally held therein by snap ring 24,

there is a poppet housing 25 providing an inlet chamber 21 communicating with cylinder 1 8 through port it and communicating with, the reservoir through an opening 23. A poppet 130, having oppositely disposed stems 32, 33, seats towards the reservoir and is normally urged against its seat by spring 3|.

A plunger w is slidably mounted in the outer end of the valve body, being urged inwardly by coil spring 4|, a main pressure chamber 42 b e ing' provided between the inner end of plunger 48 and the adjacent fend ofpoppet housing 25, chamber 42 being in communication with cylinder 9 through the annular recess 22a provided in the valve housing and through port Il Plunger 40 has a longitudinal bore 45,in' the left-hand end of' which a plug is held by a snap ring il, theplug having an opening-'48.

The inner end of the plunger bore 45 has reciprocally mounted therein a secondary plungerifl whose outer end is recessed at 5I- to receive a ball valve 55, the latter seating against the open ing through poppet housing 25. A coil spring *5! and the annular flange 50a on the auxiliary plunger, for the purpose to be later explained.

Ports 50 in plunger 40 provide communication between the plunger bore 45 and cylinder 9, and the bore 45, as well as cylinder 9, having controlled communication with the reservoir through opening 48, port 62, annular recess 63 in the valve housing, and port 42. Opening 48 is controlled by a hollow poppet 65 seating against plug 45. V Poppet 65 is normally urged against its seat by a spring 51. A plug I flts in the inner end of poppet 65, being held therein by a snap' ring 7!, and having a port 12 therethrough. A. reversely seating poppet is normally urged against its seat, closing port 12, by spring 11, and a port 80 opens through the outer end of pop pet 65.

A pull member 85 is provided on a plug threaded into the outer end of the valve hou-singto facilitate removing the valve element from the body bore, and seal rings 86 are interposed between the valve housing and the body bore. Also, seal rings '88 are interposed between the valve elements 25, 4B and 45 and the valve body. 7

For manually unseating poppet 3i! and ball 55 against pressure in the cylinders to lower a load. for instance. I provide a rotary cam 96 carried by a camshaft 9|, which shaft is iournalled in the body 5 and projects outwardly therefrom where it is operable by crank, not shown.

In operation, the suction stroke of piston [5 draws fluid from the reservoir past poppet into cylinder 8. Until the device is moved into contact with the work and encounters sufiicient resistance to movement to cause ball 55 to be unseated by thedownward or pumping stroke of piston Hi. the fluid is trapped between poppet 30 andball 55 and thus further downward movement of piston l5 relatively rapidly moves the body into contact with the work. However, when the work 7 is contacted, the resistance oifered thereb to further movement of the body, causes ball 55 to be moved off. its seat and the plunger 40 to be moved to the left against spring 4i and thus the fluid in, cylinder 8 and chamber 21 is forced into cylinder 9 to cause relative movement as between the body and plunger I 6...

During the initial movement of the body into contact'with the work. by the trapping of fluid between ball 55 and poppet 30, as before described, the body is moved away from piston l6 and thus a vacuum is created in cylinder 9. This vacuum draws fluid directly from the reservoir through the bore 4'5 of the plunger, openings 48, E2 and port l2, past poppet 65. 7

When there is pressure in cylinder 9 it acts against the shoulder or face 40a of the plunger to maintain spring 4| compressed and thus substantially eliminates pressure of plunger 40 against the ball 55, the ball during that period being normally held against its seat by the relatively light spring 51. The auxiliar plunger 5!! has its inner end exposed to fluid pressure in cylinder 9 and chamber 42 through openings 60 in the main plunger, so that fluid pressure on the respective ends of the auxiliary plunger is equalized. Thus, on each subsequent pumping stroke of piston IS, the only pressure which must be overcome to unseat ball 55 is the relatively small pressure of spring 51 plus the hydraulic pressure in the cylinder 9 acting on the area of the ball 55 covered by the seat in plug 25.

If the pressure in cylinder 9 should become too great, it is automatically relieved by poppet 4 15 unseating against its spring 11, thus allowing fluid to escape to the reservoir.

Another feature of my invention is the means now to be described for preventing too rapid downward movement of the work-lifting piston l6 under weight of the load being lifted when the pressure is released to lower the load. As

hereinbefore pointed out, the pressure is released by rotating the cam toflrst move poppet 30 off its seat and then, by virtue of stem 32, to effect a delayed movement of ball 55 off its seat. As will be noted in Fig. 1, stem 32 has an enlarged inner end 32a which is capable of substantially but not entirely filling or closing the port through the partition separating the pressure chamber 42 from the inlet chamber 21. Thus, when stem' 32 is moved to unseat ball 55, the enlarged end portion 32a enters said port and limits or restricts the discharge of fluid from the pressure chamber to the inlet chamber, commensuratel slowing down the downwardmovement of piston l6. j

I claim: a

1. A hydraulic valve comprising a body having walls defining a pressure chamber, a fluid inlet ,port through one of the walls, a check valve in the chamber and seating towards the inlet to control entry of fluid through said port, a main plunger resiliently mounted in the chamber, said main plunger having a cylindric reduced diameter inner end portion providing a shoulder face ing towards the check valve, an auxiliary plunger. mounted in said cylindric inner end portion and. having its outer end exposed tofluid pressure in the chamber, spring means urging the outer end; of the auxiliary plunger against the check valve;

and an opening in the main plunger exposing the inner end of the auxiliar plunger to fluid pressure in the chamber, whereby to substantially equalize the fluid pressure on the respective ends of the auxiliary plunger, said shoulder being ex.-, posed to fluid pressure in the chamber and being ofsufiicient area that the main plunger is moved away from the check valve in responsegto fluid pressure in the chamber. I

2. A hydraulic valve comprising a body, having walls defining a pressure chamber, a fluid'inlet port through one of the walls, a check 'valve'in the chamber and seating towards theinlet to control entry of fluid through said port, a-plunger in the pressure chamber normally yieldably ex-- erting seating pressure on the check valve, a longitudinal bore in the outer end of the plunger,

a wall closing the outer end of the bore, a port through said wall, a tubular poppet valve resil-,-

iently mounted in the bore and seating. at its outer end against the wall to normally close the port, a wall closing the inner end of said poppet valve, an opening through the last-mentioned wall, and a check valve resiliently mounted in the tubular poppet valve and normally closing .said

last-named opening, said poppet valve being yieldable to open the port in response to subateu mospheric pressure in the pressure chamber and passageway for establishing communication between the main pressure chamber and the firstmentioned pressure chamber, a check valve controlling said port and seating towards the inlet chamber, a telescopic plunger in the main pressure chamber consisting of inner and outer sections, the inner section of the plunger bearing against the check valve, spring means urging the plunger into extended position and a second spring bearing inwardly against the outer plunger section to urge said sections towards the check valve, said outer plunger section presenting an inwardly facing pressure-receiving surface exposable to pressure in the main pressure chamber and the first-mentioned chamber to urge the outer plunger section away from the inner plunger section whereby to reduce the seating pressure exerted on the check valve.

4. In hydraulic apparatus having a pressure chamber, a control valve comprising a body having a main pressure chamber and a fluid inlet chamber adapted to be connected with a source of fluid under pressure, said body presenting a port providing communication between the inlet chamber and the main pressure chamber and a passageway for establishing communication between the main pressure chamber and the first-mentioned pressure chamber, a check valve controlling said port and seating towards the inlet chamber, a telescopic plunger in the main pressure chamber consisting of inner and outer sections, the inner section of the plunger bearing against the check valve, spring means urging the plunger into extended position, a second spring bearing inwardly against the outer plunger section to urge said sections towards the check valve, said outer plunger section presenting an inwardly facing pressure-receiving surface exposable to pressure in the main pressure chamber and the first-mentioned chamber to urge the outer plunger section away from the inner plunger section whereby to reduce the seating pressure exerted on the check valve, and spring-loaded pressure release means in the plunger, said pressure release means being actuated in response to predetermined pressure in the main pressure chamber.

5. In hydraulic apparatus, a body providing pressure generating and pressure receiving chambers and a fluid reservoir, a bore in said body communicating at one end thereof with said reservoir and at spaced points intermediate its ends with said pressure generating and said pressure receiving chambers, a bushing in said bore, means for closing one end of said bushing, a first centrally apertured plug in the opposite end of said bushing or that end communicating with the reservoir, a second centrally apertured plug in said bushing spaced inwardly from said first plug, radial ports in said bushing respectively communicating the space between said plugs to said pressure generating chamber and. the space between said second plug and the closed end of said bushing to said pressure receiving chamber, a first check valve within the space between said plugs and seating against said first plug in the direction of the reservoir, a second check valve inwardly of said second plug and seating toward said plug, a piston slidably mounted in said bushing inwardly of said second plug and spring pressed toward contact with said second check valve, a spring between said piston and said second check valve, and a pressure receiving surface on said piston exposed to the pressure fluid flowing past said second valve and to the pressure of the fluid in said pressure receiving chamber whereby said piston is movable relatively to said check valve in response to pressure variations in said pressure receiving chamber to vary the tension of said spring.

, 6. Hydraulic apparatus according to claim 5, characterized in that said first valve is formed with a stem extending in one direction through said second plug toward operative engagement with said second check valve and extending in the opposite direction through said first plug for actuation from outside the valve bore to unseat said first and second check valves.

7. In hydraulic apparatus, a body providing pressure generating and pressure receiving chambers and a fluid reservoir, a bore in said body communicating at one end thereof with said reservoir and at spaced points intermediate its ends with said pressure generating and said pressure receiving chambers, a bushing in said bore, means for closing one end of said bushing, means defining a first centrally apertured wall at the opposite end of said bushing or that end communicating with the reservoir, means defining a second centrally apertured wall in said bushing spaced inwardly from said first wall, radial ports in said bushing respectively communicating the space between said walls to said pressure generating chamber and the space between said second wall and the closed end of said bushing to said pressure receiving chamber, a first check valve within the space between said walls and seating against said first wall in the direction of the reservoir, a second check valve inwardly of said second wall and seating toward said wall, a piston slidably mounted in said bushing inwardly of said second wall and spring pressed toward contact with said second check valve, a spring between said piston and said second check valve, a pressure receiving surface on said piston exposed to the pressure fluid flowing past said second valve and to the pressure of the fluid in said pressure receiving chamber whereby said piston is movable relatively to said check valve in response to pressure variations in said pressure receiving chamber to vary the tension of said spring, and means operable from outside said bushing substantially simultaneously to unseat said check valves to provide free communication between said pressure receiving chamber and said reservoir.

HERBERT E. PAGE.

REFERENCES CITED The following references are of record in the flle of this patent:

UNITED STATES PATENTS Number Name Date 514,394 VanEveren Feb. 6, 1894 1,236,583 Manning Aug. 14, 1917 1,480,598 Collis Jan. 8, 1924 1,662,922 Helmer Mar. 20, 1928 1,994,179 Raymond Mar. 12,1935 2,057,088 DeMillar Oct. 13, 1936 2,309,138 Quayle Jan. 26, 1943 FOREIGN PATENTS Number Country Date 358,692 Great Britain 1931 499,606 Great Britain Jan. 26, 1939 

